This invention relates to a traveling band screen formed of a plurality of screening elements which are attached at their ends to endless drive belts which travel around upper and lower rotary members.
In prior art screening equipment of this type the traction means usually comprises sprocket chains carrying screening elements which are pivotally attached thereto and spaced apart by several chains links. The screening elements are either of the flat type or of the basket type having a semi-cylindrical shape to increase the area of the screening surface. Since the sprocket chains are pervious to water the chain links and hinge means for the screening elements are continually subjected to the corrosive action of the liquid being screened, such as waste water. A further and even greater drawback to prior art equipment is the fact that the traction means permits leaks through which untreated liquid may by-pass the screening elements either between the screen band and the adjacent wall of the unit or between adjacent screening elements whereby this liquid will be discharged from the unit without prior treatment.